Stiffened hollow vascular device

ABSTRACT

The medical appliance has an elongated tubular shaft with a lumen extending therethrough and slots in the distal area for pressure medium entry into the lumen. A stiffening means in the form of an independent wire extends through the lumen with its proximal area extending proximally of the shaft. The proximal area of shaft is affixed to a luer-lock comprising a housing with an inner cavity and a distal end forming a muff fixedly and tightly sealed on the proximal end of the shaft.

This is a continuation of application Ser. No. 08/949,538, filed Oct.14, 1997, which is a continuation of Ser. No. 08/581,416 filed Dec. 29,1995, now abandoned.

BACKGROUND OF THE INVENTION

This invention relates to a medical appliance for pressure measurementin a blood vessel, comprising an elongated flexible shaft with aproximal area and a distal area, a lumen extending through the shaftfrom the proximal area to the distal area thereof, aperture means in thedistal area of the shaft for the entry of a pressure medium into thelumen, and stiffening means in the lumen for stiffening shaft portionswith full available shaft stiffness.

The monitoring of fluid pressures during intravascular procedures suchas angioplasty gives valuable information to the cardiologist to assessboth coronary myocardial flow reserve and collateral blood flow.

Attempts have been made to develop hollow guide wire systems which allowfor the measurement of the fluid pressure at the distal end of acatheter from the proximal end thereof. The problem with that kind ofpressure measuring guide wire is to provide an uninterrupted lumenthroughout the shaft which has to be highly flexible to conform withtortuous pathways of the blood vessels; and simultaneously, the shaftmust have an acceptably high stiffness to have pushability and assuretorque transmission as well as it must have a very good kink resistanceto avoid the risk of constrictions which could result in modification ofthe advance of pressure waves through the lumen.

For example U.S. Pat. No. 5,050,606 describes a flexible guiding memberwhich can be utilized for monitoring of fluid pressure duringintravascular procedures, or which can be utilized for directinginflation fluid to the interior of a dilatation balloon duringangioplasty procedures. This guiding member has a main elongated tubularshaft with an inner lumen extending therethrough to an axial port in thedistal end thereof. A core member is secured within the inner lumen andextends out of the distal end of the shaft. A tubular extension isdisposed about the portion of the core member which extends out of theshaft and is secured at its proximal end to the distal end of the shaft;its distal end is provided with pressure monitoring ports. The proximalend of the core is secured within the distal end of the shaft by meansof a weldment and this core wire has a cross-sectional areasubstantially less than the smallest transverse cross-sectional area ofthe inner lumen of the shaft. When the system is utilized in anindependent guide wire configuration, the distal end of the tubularextension is bonded to the core member extending therethrough and alsoto a flexible body such as a helical coil which is disposed about andsecured to the portion of the core which extends out of the distal endof the tubular extension. When the system is utilized in a so-called lowprofile steerable dilatation catheter configuration, an inflatableballoon is secured by its proximal end to the distal end of the tubularextension, and the distal end of the balloon is sealed about the portionof the core which extends out of the distal end of the tubularextension; the proximal end of the balloon is also bonded to the core.The tubular shaft is stiff and the tubular extension is diametricallyrelatively rigid to prevent kinking but it is longitudinally moreflexible than the shaft because it is this distal portion of the systemwhich must be advanced out of the guiding catheter into the patient'stortuous vasculature. The proximal end of the tubular shaft may beprovided with a removable adapter to direct inflation fluid into theinner lumen thereof. U.S. Pat. No. 4,964,409 describes the same deviceas U.S. Pat. No. 5,050,606 which is referred to hereinbefore.

European Patent Application 0 313 836 shows a pressure monitoring guidewire having a tubular shaft with an axially extending lumen. A tubularmember extends axially from the distal end of the shaft in axialalignment with the lumen thereof, such tubular member having itsproximal end received within the distal portion of the shaft. A springcoil distally ending in a tip extends axially from the shaft andsurrounds the tubular member and the shaft, the spring coil and thetubular member are soldered together at their connection areas. A solidcore extends from the distal end of the tubular member within the coil,with its proximal end welded to the tubular member and its distal endwelded to a disk located within the coil. A safety wire connects thedisk to the tip of the coil and pressure monitoring holes are formed inthe wall of the tubular extension, near the distal end thereof.Operation of this guide wire is as follows: a dilatation catheter withan inflatable balloon towards its distal end is inserted into a bloodvessel through a guiding catheter and advanced into the desired arteryalong the guide wire which is positioned so that the pressure monitoringholes are positioned beyond the distal end of the dilatation catheterwhen the balloon is in position to dilate a lesion. With the balloondilated, the pressure on the distal side of the balloon can be monitoredat the proximal end of the guide wire through the pressure monitoringholes and the luminal openings in the shaft and tubular member. Anadapter may be attached to the proximal end of the shaft for attachmentto a stopcock manifold. If an extension wire is needed, the adapter maybe removed and an extension shaft having a long tapered tip may bepress-fit into the proximal end of the tubular shaft. The originalcatheter may then be removed and replaced with an alternate catheter.The extension wire is then removed and the adapter is replaced on theproximal end of the guide wire for pressure monitoring. U.S. Pat. No.4,953,553 also refers to such a device.

Another approach is shown in the document EP 0 419 277 which describes aguide wire for use in measuring a characteristic of liquid flow in avessel, comprising a flexible elongate element in the form of a tubewith a core wire provided therein to provide additional rigidity andtorqueability to the guide wire. The core wire extends beyond the distalend of the tube into a coil spring assembly which is soldered to thetube and to the core wire. The coil spring assembly is formed of twoparts which are screwed together and the assembly is soldered to thecore wire at the region where the two portions of coil are screwedtogether. A safety wire extends from the joint of the two coils to thedistal extremity of the coil spring assembly where it is secured to atransducer carried by the distal end of the coil spring assembly. Frontand rear contacts are provided on the transducer and are connected to atwo conductor wire which extends rearwardly and interiorly of the coilspring assembly and further extends into the tube between the core wireand the interior of the tube to get out of the tube for connection to amale connector. According to a variant, an insulating sleeve may form atight fit with the exterior surface of the core wire and it may also fitwithin the tube to insulate the core from the tube so that the core andtube may serve as separate and independent electrical conductors.

European Patent Application No. 95105777.7 filed Apr. 18, 1995,describes a pressure measuring guide wire comprising an elongated hollowshaft the proximal end of which is for connection to a pressuremonitoring equipment. The distal area of the shaft comprises a pluralityof elongated slots formed in the shaft wall for pressure medium entry,whereby the resistance to kinking of that area is smaller than that ofthe proximal area of the shaft which is devoid of slots. A coil,possibly made of a radiopaque metal, is located inside the shaft underthe slots for supporting the wall and slot structure and for providing aradiopaque reference to that area. A core member is located within thecoil with proximal and distal ends formed to abut longitudinally withthe corresponding ends of the coil in order to stiffen the coil. In avariant, the core member may have its proximal end extended by a wirewhich goes proximally along and out of the lumen of the shaft. In thatcase, the supporting coil may be placed under the slots only forinsertion of the guide wire to assure resistance to kinking, when theguide wire is properly located, the supporting coil and wired coreassembly may be removed from the guide wire to maintain the shaft lumenfree of obstructions for pressure measurements.

It is an object of this application to propose a medical appliance forpressure measurement in a blood vessel which is easy and inexpensive tomanufacture, which has an appreciable handling versatility whileproviding very good qualities of resistance, steerability andpushability, and which allows a smooth advance of pressure waves in avery low profile guide wire configuration.

SUMMARY OF THE INVENTION

Accordingly, with the stiffening means consisting of an independent wireremovably extending within at least a portion of the lumen andproximally of the proximal area of the shaft, it becomes possible toselect a basic stiffness and floppyness for the shaft and to eitherwithdraw the independent wire from the shaft lumen and to replace it byanother independent wire having other characteristics, or to displacethe independent wire along the shaft lumen. The stiffness andflexibility of the shaft as well as its resistance to kinking andfloppyness are thus fully selectable and assured, and they may bemodulated by the independent wire without any detriment to the selectedshaft configuration or intrinsic qualities, and most of all withoutincreasing its outer size. The shaft therefore may be devised as a meretubing with extremely thin walls which can be safely and efficientlyadvanced through tortuous and narrow vessels as well as through acutestenoses. For pressure measurements, it suffices to withdraw theindependent wire to take advantage of a lumen which is fully free of anyobstruction, whereby a better frequency behavior for the fluid medium.And as the shaft lumen is always free of obstruction for pressuremeasurement, it is possible with a thin walled shaft to have a shaftwith a very low profile and a relatively large lumen assuring a goodflow of the fluid medium for pressure measurements.

When the independent wire is coiled, it is possible to assure therequired stiffness for the shaft while having a greater elasticity forthe independent wire, which may be of further help for extremely thinwalled shafts.

When the independent wire has an outer transverse size which decreasesfrom a proximal portion to a distal portion thereof, a greatermodulation of stiffness and floppyness is achieved for the shaft whichcan be further modified by displacement of the independent wire alongthe lumen or its mere replacement by another wire similarly devised.

With an independent wire frictionally extending within the lumen, it ispossible to achieve the lowest profile for the tubular shaft because ofthe closest relationship between independent wire and shaft whileretaining all the other characteristics of the appliance.Simultaneously, there is the advantage that the independent wire isretained in the position chosen by the practitioner for particular shaftstiffness modulation.

Where a luer-lock is removably mounted on the shaft, the practitionerhas the great advantage that he can use the pressure measurementappliance as a conventional guide wire. After insertion of the luer-lockequipped appliance proximally and distally of a stenosis for determiningthe pressure gradient, it suffices to remove the luer-lock for insertinga catheter such as a balloon catheter over the appliance which then actsas a pure guide wire which is already in place for guiding the ballooncatheter exactly at the place required. Time and cost saving is achievedand extra manipulations for inserting a new guide wire after pressuremeasurement and withdrawal of the pressure measuring device are avoidedwhile maintaining all the advantages of the appliance which becomes anefficient and low profile purpose device.

When abutment means on the independent wire are securing an end positionof the independent wire in the lumen, the practitioner may simply insertthe independent wire into the shaft without particular precautions as toits longitudinal position within the lumen, knowing that the independentwire will not go beyond a pre-fixed position in the lumen. He can alsouse that pre-fixed position as a reference for further modulation of theshaft stiffness by displacement in the independent wire.

In sum, the present invention relates to a medical appliance forpressure measurement in a blood vessel. It has an elongated flexibleshaft with a proximal area and a distal area, a lumen extending throughthe shaft from the proximal area to the distal area thereof, aperturemeans in the distal area of the shaft for the entry of a pressure mediuminto the lumen, and stiffening means in the lumen for stiffening shaftportions with full available shaft stiffness. The stiffening means maybe an independent wire removably extending within at least a portion ofthe lumen and proximally of the proximal area of the shaft. Theindependent wire may be coiled, and may have an outer transverse sizewhich decreases from a proximal portion to a distal portion thereof. Theindependent wire may frictionally extend with the lumen. The medicalappliance may have a luer-lock removably mounted on the shaft. Abutmentmeans on the independent wire may secure an end position of theindependent wire in the lumen.

DESCRIPTION OF THE DRAWINGS

These and other objects, features and advantages of the invention willbecome readily apparent from the following detailed description withreference to the accompanying drawing which shows, diagrammatically andby way of example only, preferred but still illustrative embodiments ofthe invention.

FIG. 1 is a cross sectional view of a first embodiment of the applianceaccording to the invention.

FIG. 2 is a cross sectional view of a second embodiment of theappliance.

FIG. 3 is a part cross sectional view of a third embodiment of theappliance.

FIG. 4 is a part cross sectional view of a fourth embodiment of theappliance.

DESCRIPTION OF PREFERRED EMBODIMENTS

The appliance shown in FIG. 1 comprises an elongated shaft 1 forpressure measurement in a blood vessel, having a proximal area 2 and adistal area 3. Preferably, this shaft is made of a highly flexiblematerial such as for instance Nitinol™ or Tinel Alloy™. Other materialsare possible, such as for example plastic materials.

As shown, the shaft 1 is tubular, with a lumen 4 extending therethroughfrom the proximal area 2 to the distal area 3. Aperture means in theform of slots 5 are devised in the distal area 3 of the shaft 1, for theentry of the pressure medium into the lumen 4.

The distal area 3 of the shaft 1 may terminate in a flexible assembly 6as described in the European Patent Application No. 95103006.3 filedMar. 2, 1995, comprising a first coil 7 the proximal windings of whichare spaced apart and threadedly force fitted into the distal area 3 ofthe shaft 1, and a second coil 8 the proximal portion of which isthreadingly surrounding the distal area of first coil 7 and abuttingagainst the distal end of the shaft 1. The first and second coils 7 and8 may be made of a high density metal such as tungsten to provide aradiopaque reference for the flexible assembly 6. A cylindrical core 9,preferably of stainless steel, extends through the coils 7 and 8; itsproximal portion 10 is flattened to abut longitudinally against theproximal end of coil 7, and its distal area tapers into a narrow portion11 which terminates into a weld tip 12 resting against the distal end ofthe coil 8. However, other termination configurations are also possible.

A stiffening means formed by an independent wire 13 removably extendsthrough lumen 4, with a tapering end 14 located in the distal area 3 ofshaft 1, proximally of slots 5. The independent wire 13 extends at 15proximally of the proximal area 2 of shaft 1 and it has a largerdiameter portion 151 in that area. Such an independent wire 13 may bemade, for example, of stainless steel. As shown, the independent wire 13is frictionally mounted within lumen 4 whereby it may be displacedthrough the lumen in addition to be removable therefrom.

The proximal area 2 of shaft 1 is affixed into a luer-lock 16 which isadapted to be connected to a pressure measuring equipment (not shown).The luer-lock 16 may also be connected to a fluid supply equipment (notshown) as conventionally used in the art for flushing drugs through thelumen 4 and to remove occlusions of the slots 5 to assure a goodpressure transition from the blood vessel (not shown) to the lumen 4, orto remove bubbles inside the lumen.

The luer-lock 16 comprises a housing 17 having an inner cavity 24 and adistal end which tapers at 29 to form a coupling muff 18 tightly sealed,for instance by glue, on the proximal end 19 of proximal area 2 of shaft1; the proximal end of housing 17 comprises a collar 20 with an externalthread 21. The proximal end 15 of independent wire 13 extends throughthe inner cavity 24 of the housing 17 and up to a transverse wall 152 ofinner cavity 24 against which abuts the enlarged portion 151 of theindependent wire 13.

The second embodiment shown in FIG. 2 comprises the same integers as thefirst embodiment for the shaft 1 and its distal area 3 terminating intoa flexible assembly 6 and reference is made to the correspondingdescription in relation to FIG. 1.

A stiffening means formed by an independent wire 30 removably extendsthrough lumen 4. This wire 30 also has an outer transverse size whichdecreases from its proximal area 31 to its distal area 32; instead ofthe tapering shown for the embodiment of FIG. 1, the wire has however astepwise diameter reduction as shown at 33 and 34, the last reduceddiameter section 34 being located in the distal area 3 of shaft 1,proximally of slots 5. The independent wire 30 extends at 42 proximallyof the proximal area 2 of shaft 1 and it has a larger diameter portion143 in that area abutting against the proximal end of the shaft 1. Thiswire may also be made of stainless steel and, as shown, it isfrictionally mounted within lumen 4 for displacement therein and removaltherefrom.

The proximal area 2 of shaft 1 is removably mounted into a removableluer-lock assembly 35 which is also adapted to be connected to apressure measuring equipment or fluid supply equipment as explained inconnection with the first embodiment.

The luer-lock assembly 35 comprises a first housing 36 having an innercavity 37 and a distal end which tapers at 38 to form a muff 39surrounding a portion of the proximal area 2 of shaft 1; the proximalend of housing 36 comprises a collar 40 with an external thread 41. Theproximal area 31 of independent wire 30 together with the proximal area2 of shaft 1 extend through the inner cavity 37 of first housing 36,with the proximal end 42 of wire 30 extending proximally of proximalarea 2 of shaft 1. A second housing 43 is mounted on first housing 36with an inner member 44 extending in the inner cavity 37 of firsthousing 36 and around the shaft 1. The proximal end 45 of second housing43 is for connection to a pressure measuring equipment or fluid supplyequipment (not shown) and it comprises an outer collar 46 with an innerthread 47 meshing into thread 41 of the first housing 36. Between theinner member 44 of second housing 43 and the taper portion 38 of firsthousing 36, a sealing member 49 with a distal taper 50 is located in theinner cavity 37, such a sealing member 49 also surrounding the shaft 1.

By this assembly, when the second housing 43 is screwed on the firsthousing 36, the inner member 44 is forced against sealing member 49 sothat its distal taper 50 is forced against taper 38 of inner cavity 37thereby assuring tight sealing of the assembly. Release of the secondhousing 43 frees the engagement of sealing member 49 from inner cavity37 and allows full removal of the complete luer-lock assembly 35.

The third embodiment partly shown in FIG. 3 differs from the embodimentsof FIG. 1 or FIG. 2 in that the independent wire 60 is a coiled wireremovably extending through lumen 4, with a tapering end 61 located inthe distal area of shaft 1, proximally of slots 5. Such an independentwire 60 may also be made of stainless steel and, as shown, it isfrictionally extending within the lumen 4 whereby it may also bedisplaced through the lumen in addition to be removable therefrom.

The fourth embodiment partly shown in FIG. 4 differs from theembodiments of FIG. 1 or FIG. 2 in that the independent wire 70 is madeof a coil which has a stepwise outer diameter size reduction as shown at71 and 72, the last reduced diameter section 72 being located in thedistal area 3 of shaft 1, proximally of slots 5. As for the otherembodiments, this wire may be made of stainless steel and, as shown, itis frictionally mounted within lumen 4 for displacement therein andremoval therefrom.

Variants are available without departing from the scope of theinvention. For instance, instead of having an outer transverse sizewhich decreases from a proximal portion to a distal portion, theindependent wire may have an outer transverse size which remainsunchanged from a proximal portion to a distal portion of the independentwire. Instead of frictionally extending within the lumen, theindependent wire may have an outer transverse size which is somewhatsmaller than the inner transverse size of the lumen. The independentwire may also be made of a plastic material. The shaft 1 may be made ofplastic material as indicated hereinbefore as well as it may be made ofa compound structure of a plastic material surrounded by a thin coil ofmetal, or still solely of a coil of metal. And of course, the structureson either the fixed luer-lock configuration of FIG. 1 or the removableluer-lock assembly of FIG. 2 may be replaced by other luer-lockconfigurations, fixed or removable, to the extent that they perform thesame function. Also, the enlarged diameter abutment at 151 or 143securing the end position of the stiffening wire in the lumen 4 may bereplaced by other configurations such as, for instance, studs in theindependent wire.

What is claimed is:
 1. An elongate medical device for pressuremeasurement in a blood vessel comprising: an elongate flexible tubehaving a stiffness and a lumen therein for transmitting a pressure wavefrom an at least one distal opening in the elongate tube to a proximalopening in the elongate tube; a luer-lock assembly removably mounted toa proximal end of the elongate tube, the luer-lock assembly configuredto be removed from the elongate flexible tube so that a balloon catheteror other medical device may be advanced over the elongate tube and to avascular treatment site, the luer-lock assembly comprising; a firsthousing having an inner cavity, a distal end which tapers to form amuff, the muff configured to surround a proximal portion of the elongatetube, and a proximal end comprising a collar having an external thread;a second housing mounted on the first housing and having a proximal endcomprising an outer collar with an inner thread for threaded connectionto the proximal end of the first housing and further configured forconnection to a pressure measuring device or a fluid supply system; anda sealing member positioned in the inner cavity of the first housing,the sealing member configured to seal around the elongate member whenthe first housing is threadedly engaged with the second housing; and anelongate stiffening member configured to be removably inserted into theelongate tube for varying the stiffness of the elongate tube.
 2. Theelongate medical device for pressure measurement in a blood vessel ofclaim 1 wherein the elongate stiffening member is formed from a materialfrom the group consisting of stainless steels, nickel-titanium alloys,polymers and a composite of polymers and metallic alloys.
 3. Theelongate medical device for pressure measurement in a blood vessel ofclaim 1 wherein the elongate stiffening member comprises an elongatecoil of wire.
 4. The elongate medical device for pressure measurement ina blood vessel of claim 3 wherein the elongate coil varies in diameterto change a stiffness profile of the elongate stiffening member.
 5. Theelongate medical device for pressure measurement in a blood vessel ofclaim 1 wherein the elongate stiffening member varies in stiffness alongits length.
 6. The elongate medical device for pressure measurement in ablood vessel of claim 1 wherein the elongate stiffening member furthercomprises an abutment means near a proximal end of the stiffeningmember, the abutment means preventing the stiffening member from beinginserted beyond a certain point in the flexible tube.
 7. The elongatemedical device for pressure measurement in a blood vessel of claim 1wherein the elongate stiffening member further comprises a tapereddistal end configured to facilitate insertion of the stiffening memberinto the flexible tube.
 8. The elongate medical device for pressuremeasurement in a blood vessel of claim 1 further comprising a flexibleassembly attached to a distal end of the elongate tube and configured toreduce any trauma to the vasculature.
 9. A medical device forintravascular blood pressure measurement comprising: an elongateflexible tube having a stiffness and a lumen therein for transmitting apressure wave from an at least one distal opening in the elongate tubeto a proximal opening in the elongate tube; an elongate stiffeningmember configured to be removably inserted into the elongate tube forvarying the stiffness of the elongate tube; and a removable means forcoupling the tube to the stiffening member, the removable meanscomprising a means for housing a sealing member, the sealing memberpositioned in the housing means such that the sealing member sealsaround the elongate tube.
 10. The medical device for intravascular bloodpressure measurement of claim 9 wherein the elongate stiffening memberis formed from a material from the group consisting of stainless steels,nickel-titanium alloys, polymers and a composite of polymers andmetallic alloys.
 11. The medical device for intravascular blood pressuremeasurement of claim 9 wherein the elongate stiffening member comprisesan elongate coil of wire.
 12. The medical device for intravascular bloodpressure measurement of claim 9 wherein the elongate coil varies indiameter to change a stiffness profile of the elongate stiffeningmember.
 13. The medical device for intravascular blood pressuremeasurement of claim 9 wherein the elongate stiffening member varies instiffness along its length.
 14. The medical device for intravascularblood pressure measurement of claim 9 wherein the elongate stiffeningmember further comprises an abutment means near a proximal end of thestiffening member, the abutment means preventing the stiffening memberfrom being inserted beyond a certain point in the flexible tube.
 15. Themedical device for intravascular blood pressure measurement of claim 9wherein the elongate stiffening member further comprising a tapereddistal end configured to facilitate insertion of the stiffening memberinto the flexible tube.
 16. The medical device for intravascular bloodpressure measurement of claim 9 further comprising a flexible assemblyattached to a distal end of the elongate tube and configured to reduceany trauma to the vasculature.
 17. The elongate medical device forpressure measurement in a blood vessel of claim 9 wherein the removablemeans for coupling the tube to the stiffening member comprises: a firsthousing having an inner cavity, a distal end which tapers to form amuff, the muff configured to surround a proximal portion of the elongatetube, and a proximal end comprising a collar having an external thread;a second housing mounted on the first housing and having a proximal endcomprising an outer collar with an inner thread for threaded connectionto the proximal end of the first housing and further configured forconnection to a pressure measuring device or a fluid supply system; anda means for sealing about the elongate tube when the first housing isengaged with the second housing.
 18. An elongate medical device forpressure measurement in a blood vessel comprising: an elongate flexibletube having a proximal area, a distal area, a lumen extending throughthe tube from the proximal area to the distal area, and aperture meansin the distal area of elongate tube to a proximal opening in theelongate tube; and a luer-lock assembly removably mounted to a proximalend of the elongate tube, the luer-lock assembly configured to beremoved from the elongate flexible tube so that a balloon catheter orother medical device may be advanced over the elongate tube and to avascular treatment site and comprising; a first housing having an innercavity, a distal end which tapers to form a muff, the muff configured tosurround a proximal portion of the elongate tube, and a proximal endcomprising a collar having an external thread; a second housing mountedon the first housing and having a proximal end comprising an outercollar with an inner thread for threaded connection to the proximal endof the first housing and further configured for connection to a pressuremeasuring device or a fluid supply system; and a sealing memberpositioned in the inner cavity of the first housing, the sealing memberconfigured to seal around the elongate tube when the first housing isthreadedly engaged with the second housing.
 19. The elongate medicaldevice for pressure measurement in a blood vessel of claim 18 whereinthe elongate tube is formed from a material from the group consisting ofstainless steels, nickel-titanium alloys, polymers and a composite ofpolymers and metallic alloys.
 20. The elongate medical device forpressure measurement in a blood vessel of claim 18 further comprising aflexible assembly attached to a distal end of the elongate tube andconfigured to reduce any trauma to the vasculature.